Apparatus and method for a shape memory alloy mandrel

Patent metadata

Field	Value
Publication number	US-9919505-B2
Application number	US-201414340914-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Jul 25, 2014
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

In one or more aspects of the present disclosure, a mandrel is disclosed. The mandrel having a shape memory alloy (SMA) shell having a longitudinal axis, an interior extending along the longitudinal axis and an exterior contour, the SMA shell being configured to interface with a structure to be cured, and at least one SMA actuation member disposed within the interior and connected to the SMA shell, where the at least one SMA actuation member is configured to exert pressure against the SMA shell effecting an interface pressure between the exterior contour of the SMA shell and the structure to be cured where the exterior contour has a predetermined actuated shape that corresponds to a predetermined cured shape of the structure to be cured.

First claim

What is claimed is:

1. A mandrel comprising:
a shape memory alloy (SMA) shell having a longitudinal axis, an interior extending along the longitudinal axis and an exterior contour, the SMA shell being configured to interface with a structure to be cured;
at least one SMA actuation member disposed within the interior and connected to the SMA shell, where the at least one SMA actuation member is configured to exert pressure against the SMA shell effecting an interface pressure between the exterior contour of the SMA shell and the structure to be cured where the exterior contour has a predetermined actuated shape that corresponds to a predetermined cured shape of the structure to be cured;
longitudinally extending SMA members connected to the SMA shell, the longitudinally extending SMA members being configured to effect one or more of a longitudinal bending or torsion of the mandrel about the longitudinal axis; and
a second SMA shell, the at least one SMA actuation member being disposed between and connected to the SMA shell and the second SMA shell.

2. The mandrel of claim 1 , wherein the at least one SMA actuation member further comprises at least one SMA element arranged in a substantially sinusoidal configuration.

3. The mandrel of claim 2 , wherein the at least one SMA element may be arranged in a substantially sinusoidal configuration having unequally spaced sinuses.

4. The mandrel of claim 1 , further comprising SMA actuation fins connected to the second SMA shell and being configured to effect an axial pressure, along the longitudinal axis, between the structure to be cured and the exterior contour of the SMA shell.

5. The mandrel of claim 4 , further comprising an axially extending hub connected to the SMA actuation tins and being configured to stabilize the SMA actuation fins along the longitudinal axis.

6. The mandrel of claim 4 , wherein at least one of the SMA actuation fins and the at least one SMA actuation member are configured to effect differing pressure regions against the SMA shell.

7. The mandrel of claim 1 , wherein the at least one SMA actuation member effects a medially outward pressure on the SMA shell.

8. The mandrel of claim 1 , wherein the SMA shell has a substantially non-uniform cross section in one or more of radial and longitudinal directions with respect to the longitudinal axis so as to form at least a first interior region and a second interior region.

9. The mandrel of claim 8 , wherein the at least one SMA actuation member is configured to exert substantially the same pressure against the SMA shell in the first interior region and the second interior region.

10. A mandrel comprising:
a first shape memory alloy (SMA) shell having a longitudinal axis, an exterior contour and forming an interior space, the exterior contour of the first SMA shell being configured to interface with a composite to be cured; and
at least one SMA actuation member disposed within the interior space and being configured to effect regions of expansion pressure against the first SMA shell and effecting a transfer of expansion pressure to the composite to be cured;
at least one longitudinally extending SMA member connected to the first SMA shell, the longitudinally extending SMA members being configured to effect one or more of a longitudinal bending or torsion of the mandrel about the longitudinal axis; and
a boundary SMA shell disposed outward of the first SMA shell and the at least one longitudinally extending SMA member is disposed between and connecting the first SMA shell and the boundary SMA shell so as to transfer expansion pressure from the at least one SMA actuation member to the composite.

11. The mandrel of claim 10 , wherein the regions comprise at least a first pressure region and second pressure region where the pressure exerted against the first SMA shell in the first pressure region is different than a pressure exerted against the first SMA shell in the second pressure region.

12. The mandrel of claim 10 , wherein the at least one SMA actuation member is configured to provide at least a radial and axial expansion pressure relative to the longitudinal axis.

13. The mandrel of claim 10 , wherein the at least one longitudinally extending SMA member comprises a plurality of longitudinally extending SMA rods spaced about a circumference of the first SMA shell.

14. The mandrel of claim 10 , wherein the at least one SMA actuation member comprises one or more of a circumferentially arranged SMA and a radially arranged SMA element.

15. A method of forming a composite structure comprising:
placing the composite structure to be cured around a shape memory alloy (SMA) mandrel;
exerting a pressure against an SMA shell of the SMA mandrel so that the pressure is transferred to the composite structure to be cured by an exterior contoured surface of the SMA mandrel with at least one SMA actuation member disposed within an interior of the SMA mandrel and connected to the SMA shell where the exterior contour has a predetermined actuated shape that corresponds to a predetermined cured shape of the composite structures;
exerting one or more of a longitudinal bending or torsion of the SMA mandrel, about a longitudinal axis of the SMA mandrel, with at least one longitudinally extending SMA member connected to the SMA shell; and
wherein a boundary SMA shell is disposed outward of the SMA shell and the at least one longitudinally extending SMA member is disposed between and connecting the SMA shell and the boundary SMA shell for transferring expansion pressure from the at least one SMA actuation member to the composite structure.

16. The method of claim 15 , wherein the pressure is exerted in multiple directions relative to the longitudinal axis of the SMA mandrel.

17. The method of claim 15 , further comprising placing an actuation shell over the composite structure to be cured where the SMA mandrel effects compression of the composite structure to be cured against the actuation shell.

18. The mandrel of claim 11 , wherein the at least one SMA actuation member further comprises at least one SMA element arranged in a substantially sinusoidal configuration.

19. The mandrel of claim 1 , wherein the at least one SMA actuation member is configured to effect at least a first pressure region and a second pressure region where the pressure exerted against the SMA shell in the first pressure region is different than a pressure exerted against the SMA shell in the second pressure region.

20. The mandrel of claim 19 , wherein the first pressure region and the second pressure region are arranged axially along the longitudinal axis or are arranged perimetrically about the longitudinal axis.

Assignees

• Boeing Co

Inventors

• Shome Moushumi
• Apdalhaliem Sahrudine
• Calkins Frederick T
• Ashmawi Waeil M
• Meredith Kimberly

Classifications

• B29L2031/3076

  Aircrafts (blades, propellers B29L2031/08) · CPC title

• B29C70/446

  Moulding structures having an axis of symmetry or at least one channel, e.g. tubular structures, frames · CPC title

• B29C33/485

  cores or mandrels (collapsible mandrels for shaping tube ends B29C57/02; collapsible mandrels for winding and joining B29C53/824) · CPC title

• B29C33/38 Primary

  characterised by the material or the manufacturing process (B29C33/44 takes precedence) · CPC title

• B32B37/18

  involving the assembly of discrete sheets or panels only · CPC title